1. Field of the Invention
The present invention relates to an optical film, a polarizing plate including the same, and a display device.
2. Discussion of Related Art
A retardation film may be disposed at one or both sides of a liquid crystal cell to enhance a characteristic of a viewing angle of a liquid crystal display (LCD) as disclosed in Japanese Patent Publication No. 1996-321381. The retardation film may also be used to prevent reflection and ensure visibility in a reflective LCD or organic light emitting device (OLED).
The retardation film is a ½ or ¼ wavelength retardation film depending on retardation characteristics. The ½ or ¼ wavelength retardation films have been known so far to exhibit retardation differences according to wavelengths, and therefore are operated in a limited range of wavelengths. For example, in many cases, a film serving as a ¼ wavelength retardation film with respect to light having a wavelength of 550 nm may not be operated with respect to light having a wavelength of 450 or 650 nm.